Improved two-dimensional electron gas transport characteristics in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor with atomic layer-deposited Al 2 O 3 as gate insulator

The effects of Al 2 O 3 gate insulator grown by atomic layer deposition (ALD) system on the two-dimensional electron gas (2DEG) transport characteristics in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor (MISHEMT) were investigated. The shape of the electron lateral distribution in the quantum well at AlGaN/GaN interface was found to be slightly influenced by the Al 2 O 3 thin layer. The drift mobility ( μ d ) of the electrons in ALD- Al 2 O 3 / AlGaN / GaN MISHEMT is increased due to the surface passivation effects of the included dielectric layer. The higher dynamic channel current of the MISHEMT indicates that the electron saturation velocity ( v sat ) is also increased. These results show the improvement of the transport characteristics of 2DEG in Al 2 O 3 / AlGaN / GaN MISHEMT by the excellent properties of the Al 2 O 3 grown by ALD.